Abstract：In Hadoop MapReduce environments, if the execution time of jobs is forecast, can make more appropriate decisions when allocating resource, scheduling tasks or balancing load. This paper proposed an online method to predict the execution time of jobs after analyzing the execution mode of Hadoop MapReduce jobs. The method can predict the execution time according to the progresses of different phases, combining with historical information. It has been implemented in Hadoop-0. 20. 2, and evaluated in a Linux cluster with19 nodes. The experiment results show that the difference between the real and predicted results is around 2%in a best case.

Keyword：job execution time;online prediction method;distributed computing;parallel processing;MapReduce;